Shaker screen



Oct. 25, 1938.

S. P. SOWDER SHAKER SCREEN Filed Jan. 30, 1937 3 Sheets-Sheet l Inventor '57 50206202" A iiorne ys S. P. SOWDER Oct. 25, 1938.

SHAKER SCREEN Filed Jan. 50, 1957 3 Sheets-Sheet 2 Inventor J. W awder M ,fimnan,

Attorneys S. P. SOWD ER Oct. 25, 1938.

SHAKER SCREEN Filed Jan. 30, 1937 3 Sheets-Sheet 3 Inventor Patented Oct. 25, 1938 UNITED STATES PATENT OFFICE SHAKER SCREEN Seth P. Sowder, Hardburly, Ky. Application January 30, 1937, Serial No. 123,257

2 Claims.

This invention relates to shaker screens of the type used for screening coal.

An object of the present invention is to provide what-is commonly known in the art as a nonstop-up screen, that is to say a screen which is so provided that lumps of coal will not be permitted to lodge in the openings or interstices of the screen as will preclude a proper screening of the coal.

Briefly, the invention consists in the provision in a shaker screen of the character mentioned of means for dislodging lumps of coal that may become lodged within the interstices of the screen; and the invention together with its objects and advantages will be best understood from a study of the following description taken in connection with the accompanying drawings wherein:

Figure 1 is a side elevational view illustrating the application of the invention to a shaker screen.

Figure 2 is a transverse sectional view taken substantially on the line 22 of Figure I.

Figure 3 is a fragmentary detail view mostly in top plan.

Figure 4 is a longitudinal sectional view through the screen and Figure 5 is a fragmentary detail vertical sectional view illustrating certain structural features hereinafter more fully referred to.

Referring to the drawings by reference numerals it will be seen that 5 indicates generally the shaker screen, the same in the present instance being suspended through the medium of hanger rods 6 for reciprocatory movement to effect a screening of the coal or the like placed on the screen 5. Obviously any-suitable mechanism may be employed for reciprocating or agitating the screen 5.

In the present instance the screen 5 is shown as consisting of a pair of side members 1 between which are mounted a plurality of stepped bottom plates 8.

The plates 8 at their lapping ends are provided in alternation with relatively large openings or interstices 9 formed therein, and depending lugs I!) that rest on the lapped edges of the plates 8 as clearly shown in Figure 4.

From the above, it will be understood that as the screen 5 is reciprocated the smaller pieces or lumps of coal pass through the openings or interstices 9 while the larger lumps of coal progress from one end to the other end of the screen to discharge from the last mentioned end of the screen.

In accordance with the presentinvention there are mounted between the sides I of the screen 5 and disposed directly beneath the lapped edges of the bottom plates 8 a plurality of shafts H.

Each shaft II is equipped with a plurality of knocker arms l2. Each arm I2 is provided at one end with a split clamp l3 through the medium of which the arm is secured to its shaft II at the desired angular position of adjustment relative to the shaft.

The arms II on the respective shafts are positioned so as to work through the openings or interstices 9 for the purpose of dislodging lumps of coal that may become lodged or wedged within the interstices thus detracting from the effective. operation of the screen.

On at least one end thereof the shafts II are provided with crank arms l4 and as clearly shown in Figures 1 and 2 the arms I4 at one end are provided with split clamps I5 through the medium of which the arms I4 are secured to their respective shafts II at any desired position of angular adjustment.

The arms M are provided with elongated slots [6 that accommodate bolts l'l through the me-. dium of which a connecting rod I8 is operatively connected with the arms M. This slot 16 and bolt I1 connection between the rod l8 and the respective arms l4 permits of an adjustment between the rod I 8 and the respective arms l4 whereby the stroke of the members l2 may be varied as found desirable.

Pivotally connecting one end of the rod [8 to fixed member I 9 is a link 20, so that as the shaker screen reciprocates rod I8 will impart oscillatory motion to the shafts II for oscillating the shafts in unison to the end that the arms l2 are continuously swinging in a vertical plane for dislodging lumps of coal as may become lodged within the interstices or openings 9.

In connection with the above, it will be understood that in operation the coal on the shaker screen progresses forwardly on the forward stroke of the screen while on the return stroke of the screen the arms or knockers l2 move upwardly through the openings or interstices 9 for discrank arms being provided with clamps embraca ing said shafts for securing the arms on the respective shafts at the desired angular position of adjustment, said crank arms being also provided with slots, a rod'for connecting said crank arm, and bolts carried by said rod and engaging in the slots of the crank arms whereby a connection, permitting of an adjustment of the stroke of said shafts, is provided for between said rod and said crank arms.

2. In combination, a screen for sizing coal suspended for endwise reciprocating movement and having a bottom provided with transversely extending rows of openings therein, and means for clearing said openings comprising a plurality of transverse rock shafts related to said rows of openings, respectively, and mounted on said screen beneath the related rows, each shaft having fast thereon a plurality of bar-like rocker arms swingable under rocking movement of the shaft into and out of the related row of openings, to clear the same, said arms, forming together with said openings a grate constantly open to the passage of coal therethrough, and means to effect rocking movement of said shafts as an incident to reciprocating movement of the screen and including devices for varying the degree of rocking movement thereof.

SETH P. SOWDER. 

